When a person inhales, air passes into lungs and flows through progressively smaller airways, which are surrounded by smooth muscles. When these smooth muscles are in a pathological condition (e.g., swelling, constriction, etc.), various pulmonary diseases may result such as, for example, asthma. Asthma affects about 300 million people worldwide, and current therapeutic methods for treating asthma include immunological modulation, anti-inflammation, and relaxation of airway smooth muscle. Hormones or their derivatives (e.g., glucocorticoid, beta-adrenogenic agonists) are generally used in these therapeutic methods. However, uses of hormones and these derivatives might have risk of toxicity to liver, kidney and other organs.